Re: [RFC PATCHC 2/3] idle: store the idle state the cpu is

[Peter Zijlstra]

On Tue, Apr 15, 2014 at 02:43:30PM +0200, Peter Zijlstra wrote:
> On Fri, Mar 28, 2014 at 01:29:55PM +0100, Daniel Lezcano wrote:
> > @@ -143,6 +145,10 @@ static int cpuidle_idle_call(void)
> >  			if (!ret) {
> >  				trace_cpu_idle_rcuidle(next_state, dev->cpu);
> >  
> > +				*power = &drv->states[next_state].power;
> > +
> > +				wmb();
> > +
> 
> I very much suspect you meant: smp_wmb(), as I don't see the hardware
> reading that pointer, therefore UP wouldn't care. Also, any and all
> barriers should come with a comment that describes the data ordering and
> points to the matchin barriers.

Furthermore, this patch fails to describe the life-time rules of the
object placed there. Can the objected pointed to ever disappear?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/